Surface ozone at a coastal suburban site in 2009 and 2010: Relationships to chemical and meteorological processes

Air quality and meteorological measurements were conducted at the Chemistry and Physics of the Atmospheric Boundary Layer Experiment (CAPABLE) site during the summers of 2009 and 2010 in Hampton, Virginia. Significant differences in surface ozone mixing ratios were observed between the two years and are correlated with meteorological parameters such as temperature, humidity, and cloud cover. The number of exceedance days for ozone set by the U.S. Environmental Protection Agency within this region has been decreasing for the past decade, especially in urban areas. There were no exceedance days with respect to ozone in 2009, and there were four exceedance days in 2010. The four highest ozone daily maxima and the two exceedance days observed during the 2010 measurement period were coincident with sea breeze phenomena. In one case, surface ozone increased at a rate of 14.6 ppb h−1 with the passage of a sea breeze front. A comprehensive multilinear regression model as well as an operational forecast was unable to resolve the high ozone observed during sea breeze events. As the number of exceedance days per year within this region continues to decrease, accurately forecasting sea breezes may become more important for the forecasting of pollution events. Key Points Sea breeze phenomena contribute to ozone exceedances in this region Air quality differences were observed between 2009 and 2010 in this region Maximum daily ozone can be predicted using as few as three meteorological variables